Protect your plants from freeze damage
Wednesday, January 8, 2014 12:00 AM
Most established and, especially, adapted plants, probably will not be affected by this cold spell except may be in coastal counties. It has been cool to moderately cold in the more northern areas of Mississippi, so adapted plants have fairly well hardened off. However, the temperature during a freeze, when it occurs, and for how long it occurs are all factors that gauge how damaging a freeze will be. If we have a really prolonged duration of freezing conditions, this is when the most damage will be done.
Protect plants that are in containers either by placing them inside a protective structure (house, garage, greenhouse, or shed) or by placing a protective covering over them. Container plants are especially susceptible to cold temperatures because their roots are above ground. Roots that are damaged by cold temperatures may not show immediate signs of damage, but these plants will show signs of stress when temperatures increase.
Push together container plants that are left outside and mulch or cover them to decrease heat loss from the sides of the containers. Wrap the base of the containers in plastic, burlap, or blankets to reduce heat loss.
We have not seen weather this cold in the last 20 years. There have been a lot of plants established in areas marginal to their cold tolerance. Two that I have seen are frequently planted are palms and assorted citrus trees. There are varying degrees of cold hardiness among citrus tree with kumquats and satsumas being some of the more cold tolerant. The temperatures that are being predicted will injure even the most cold-hardy of these without some form of protection.
The same can be said about some the palms planted along the coast. Even the most cold tolerant of them can be injured by temperatures in the mid-teens.
Some things you can do to help all plants during this cold spell is to apply mulch to the roots to insulate them. The mulch will also keep winter weeds under control and reduce the need to water the plants. If the soil around your plants is dry, water thoroughly. Remember, as water freezes it gives off heat.
For plants such as small citrus or small palm trees, you can build a frame over the plant or plants, cover with plastic, and seal plastic to the ground with soil. This plastic traps moisture and warm air as it radiates from the soil. It also knocks off the cold wind. Be careful not to allow plastic to come in contact with plants or damage will occur at the points of contact. Put an incandescent light bulb in the enclosure if temperatures in the teens are forecasted.
If you only drape material over a plant to protect it, make sure the cover comes all the way to the ground. Blankets or tarps are better than plastic, but anything is better than nothing. Again, foliage in direct contact with the cover might be damaged but the plant will be saved.
If the plants are too large to build frames, place Christmas tree lights (not the LED type) in citrus trees or around the trunk of palm trees. You could also used water pipe heating tape to wrap trunks. If you can protect and save the trunk of citrus trees, they will grow back. Palm trees are more difficult to protect since their growing point is in the tip of the tree.
Another option for citrus tree is to spray them with water during the freeze period. Especially coat the scaffold branches with this freezing water. An ice-coated citrus tree is a sight to behold! You will probably lose a year of production but you will not have to replace the tree.
After the freezing event it is best not to do anything for a few weeks. Allow enough time for a freeze damage to show up in the plants. You might even wait to new growth starts in the spring. This is early January so there is a lot of time left this winter for more freezes.